Revert back old commit 0561dbc for non-gcc compilers

FCC fails to build the package if the iterator inherits from Edges::const_iterator.
This should go into the upstream for the portability. I have tested the patch with
the small reads suggested by the Project Wiki and obtained the same results
without the patch. (MPI and non-MPI apps are checked) 

Shaun, if you still remember as to why the commit was necessary, I'd like to
hear from you.